Catalyst for removing sulfur and metal contaminants from heavy crudes and residues

ABSTRACT

A catalyst for the hydrotreatment of heavy crudes and their residues, and a method of preparing same, is disclosed, which has significant simultaneous hydrodemetallizing and hydrodesulfurizing activity. The catalyst is prepared by successively impregnating an extruded refractory support with a Group VIb and a Group VIII metal, calcining the pellet thus produced, and presulfurizing same. Pore volume of the catalyst ranges between 0.50 and 1.2 ml/g, total surface area ranges between 120 and 140 m 2  /g, at least 60% of said pore volume consists of pores having diameters greater than 100 Å, and x-ray photoelectron spectroscopy signal band strength ratios are as follows: I(Me VIb)/I(refractory metal) is between 5 and 8, and I(Me VIII)/I(refractory metal) is between 1 and 5. The novel catalyst has a useful life greater than conventional catalysts for the simultaneous hydrodemetallization and hydrodesulfurization of continuous feeds of heavy hydrocarbons, as shown by the fact that it exhibits no substantial reduction in catalytic activity over an 80 day period.

CROSS REFERENCE TO RELATED APPLICATION

This is a division of application Ser. No. 724,969 filed Apr. 19, 1986,which is now U.S. Pat. No. 4,588,709 which is a continuation-in-part ofapplication Ser. No. 563,197, filed Dec. 19, 1983 now U.S. Pat. No.4,520,128.

BACKGROUND OF THE INVENTION

The use of catalysts for the demetallization of hydrocarbons ofpetroleum origin has been known for some time. Demetallization of suchcrudes is desirable in order to reduce the concentrations ofcontaminating metals such as vanadium, nickel, and iron, because thecontaminating metals reduce the useful life of contacted catalysts usedin refining operations, such as hydrocracking, hydrodesulfurization andcatalytic cracking. These contaminating metals act as poisons to theaforesaid contacted catalysts used in refining operations and thereforerequire that said contacted catalyst be replaced after a shorter periodthan would otherwise occur.

Various metals have been used as catalysts in eliminating contaminatingmetals and sulfur present in petroleum hydrocarbons. For example, theelimination of metals can be accomplished by using bauxite as acatalyst, see U.S. Pat. Nos. 2,687,983 and 2,769,758, using iron oxideand alumina, see U.S. Pat. No. 2,771,401, or using macroporous aluminasin a boiling bed, see U.S. Pat. No. 3,901,792.

A multi-step hydrotreatment method overcoming some disadvantages ofsingle step procedures is disclosed in U.S. Pat. No. 3,696,027. Thismulti-stage process consists of passing a heavy hydrocarbon, at highpressures and temperatures and in the presence of hydrogen, through athree-phase reactor which uses macroporous catalyst particles. Thiscatalyst has a high capacity for accepting metals but a lowdesulfurizing activity. The effluent as treated by the first macroporouscatalyst is then subjected to a fixed-bed reactor phase at a hightemperature and pressure together with hydrogen, the fixed bedcontaining catalyst particles having a moderate desulfurizing activity.Finally, the effluent from the preceding reactor is subjected to a thirdfixed-bed reactor using high temperatures and pressures, once again withhydrogen, the fixed bed in this phase containing catalyst particleswhich have a high desulfurization activity.

SUMMARY OF THE INVENTION

Accordingly, a principal object of the invention is to provide acatalyst, and a method for preparing same, for the simultaneoushydrodemetallization and hydrodesulfurization of heavy crudes.

A still further object of the present invention is to provide acatalyst, and a method for preparing same, which is capable ofsimultaneously hydrodemetallizing and hydrodesulfurizing heavy crudesover a long period of time, such that no significant decrease indemetallizing or desulfurizing activity occurs over at least 80 days ofcontinuous processing of a heavy crude.

Further objects and advantages of the present invention will becomeapparent from the Detailed Description of Preferred Embodiments whichfollows.

In accordance with the present invention it has now been found that theforegoing objects and advantages of the present invention may be readilyobtained. Thus, the method of the present invention comprises a methodfor the preparation of a catalyst for the hydrotreatment of heavy crudesand their residues having high metal and sulfur contents, whichcomprises: providing a refractory support structure; impregnating thesupport structure with at least one compound containing a metalliccomponent selected from Group VIb of the Periodic Table and Group VIIIof the Periodic Table, said Group VIb compound being present in theimpregnated support in concentrations ranging from 5 to 30% by weight,and said Group VIII compound being present in said support inconcentrations ranging from about 1 to 5% by weight; drying theimpregnated support; and calcining the dried impregnated support with ahot dry air current at a temperature of about 400° to 600° C., using anair volume of 40-100 ml/(g catalyst) (hour), whereby a catalystpossessing significant simultaneous demetallizing and desulfurizingactivity over a long useful life is obtained.

The catalyst of the present invention comprises a catalyst for thesimultaneous demetallization and desulfurization activity, comprisingthe following steps: extruding a support comprising alumina, whichsupport has a pore volume between 0.8 and 0.9 ml/g, an average porediameter of about 250 Å, a surface area of about from 130 to 300 m² /g,and a pellet size ranging between 1/60 inch to 1/8 inch; impregnatingsaid support with a first metallic compound having a metallic componentand a nonmetallic component, said metallic component being selected fromthe group consisting of molybdenum, tungsten and mixtures thereof, saidimpregnation taking place in a buffered aqueous solution of said firstmetallic compound during a period of about 4 hours at ambienttemperature and moderate agitation so as to obtain a catalystcomposition of 5-30% by weight of said metallic component; drying theimpregnated support at about 120° C. for about 24 hours at atmosphericpressure; impregnating said dried support with a second metalliccompound having a metallic component and a nonmetallic component, saidmetallic component being selected from the group consisting of cobalt,nickel and mixtures thereof, said second impregnation taking place in anaqueous solution of said second metallic compound during a period offrom about 2 to about 3 hours, so as to obtain a catalyst composition of0.1-8% by weight of said second metallic component; drying thereimpregnated support at about 120° C. for about 24 hours; calcining thedried support at about 600° C. for a period ranging from 1 to 24 hours,with a dry air circulation of 50 ml/(hr.) (g support); andpresulfurizing the calcined support at a temperature between 200° and400° C., using a sulfur material selected from the group consisting ofsulfur, mercaptans, hydrogen sulfide and mixtures thereof, whereby aneffective catalyst is obtained.

In accordance with a preferred embodiment, a refractory oxide supportstructure is extruded and impregnated with metals from Group VIb andGroup VIII of the Periodic Table, such that a distribution of mesopores(100-600 Å) and macropores (600 Å+) is obtained whereby the average porediameter ranges between 150 and 300 Å.

In addition, the catalyst preferably comprises a refractory oxidesupport and a plurality of deposited active metals, wherein the catalysthas a pore volume between 0.50 and 1.2 ml/g, at least 60-80% andpreferably at least 90% of which volume consists of pores havingdiameters greater than 100 Å, said catalyst also having a surface areaof 120-400 m² /g, and showing x-ray photoelectron spectroscopy signalband strength ratios of 5<I(metal VIb)/I(refractory metal)<8 and1<I(metal VIII)/I(refractory metal)<5, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the relation between hydrodemetallizationconstant K_(v) ^('), hydrodesulfurization constant K_(s) ^('), and thetotal pore volume of several catalysts tested in Example 2; and

FIG. 2 is a graph showing the relation between K_(v) ^('), K_(s) ^('),and average pore diameter of several catalysts tested in Example 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Simultaneous demetallization and desulfurization of a heavy crude can beaccomplished by using catalysts having a controlled distribution ofmesopores and macropores. The term "mesopores" refers to the portion ofthe total pore volume consisting of pores having a diameter in the rangeof 100 to 600 Angstroms, as determined by the nitrogen absorption methoddisclosed by E. V. Ballou and O. K. Dollem in Analytical Chemistry,Volume 32, page 532 (1960). The term "macropores" refers to the portionof the total pore volume which consists of pores having a diametergreater than 600 Angstroms, as determined by a Mercury PenetrationPorosimeter 915-2, manufactured by Micromeritics Corporation, Georgia,using a 140° contact angle and a mercury surface tension of 474 dynesper centimeter at 25° C. The term "total pore volume" of the catalyst asused in this specification refers to the sum of mesopore volume and themacropore volume as determined by the above methods.

The term "demetallization" as used herein refers to the elimination of70% of the metals contained in heavy crudes or residues, as effected byhaving petroleum hydrocarbons pass across a reaction zone containing thecatalyst of the invention. The term "desulfurization" likewise refers tothe elimination by the catalyst of 70% of the sulfur present in theheavy hydrocarbon before passage through the reaction zone.

In preparing the catalyst of the present invention, a refractory oxidesupport is used and the support as well as the resultant catalyst hasthe following characteristics: total pore volume ranging between 0.50and 1.20 ml/gram (preferably about 0.8 to 0.9 ml/g); average porediameter varying between 150 and 300 Angstroms (preferably about 250 Å);and surface area varying between 120 and 400 m² /gram (preferably about130-300 m² /g). The catalyst supports should be extruded in pellet sizeswhich may fall in the range of from 1/60 to 1/8 inch. The supportmaterial which will meet the above specifications may be selected fromthe following refractory oxides: alumina, silica, magnesia, zirconia,titania or a mixture of the aforementioned, as used alone or impregnatedwith stabilizing materials. Alumina, silica or a mixture thereof arepreferred support materials.

After the supports are extruded, compounds containing the catalyticallyactive metals are deposited on the supports by impregnation. Variousmethods of impregnating active metals on a refractory oxide support areknown in the art. In general, they can be classed into successiveimpregnation methods, dry impregnation methods, and co-impregnationmethods.

In a successive impregnation method, the support is first impregnatedwith any one of the active metals, and is then passed to a drying and/orcalcination stage. The cycle is repeated for the second and subsequentactive metals.

In carrying out a dry impregnation, an exact volume of active metalcompound solution equal to the retention volume of the refractory oxidesupport is added which will then be completely absorbed.

Co-impregnation is carried out by placing the refractory oxide orsupport in contact with a solution containing all of the active metalsof the catalyst. The impregnated catalyst then proceeds to the dryingand/or calcining stages.

The present invention uses two stages of successive impregnation. Anextruded refractory oxide support which has the above-mentioned physicalspecifications is put into contact with, for example, a solution ofammonium molybdate, ammonium paramolybdate, molybdenum oxalate ormolybdenum pentachloride, or with a corresponding soluble salt ofanother Group VIb metal. In order to obtain a composition of 5-30% byweight of molybdenum or other Group VIb metal on the support, the firstimpregnation stage should last about 4 hours at ambient temperature andmoderate agitation. The pH of the impregnating solution is held constantwith the addition of a buffer solution. At the end of the firstimpregnation period, the Group VIb solution is drained off and the moistimpregnated catalyst is placed into a furnace with air circulation at120° C. and at atmospheric pressure for 24 hours.

The refractory oxide support as impregnated with Group VIb metal is thenput into contact with an aqueous cobalt nitrate or nickel nitratesolution in order to obtain a concentration of 0.1 to 8% by weight ofnickel or cobalt on the catalyst. The period of the second impregnationranges from 2 to 3 hours. The catalyst is dried for 24 hours, using atemperature of 120° C., and calcined at 600° C. for a period of from 1to 24 hours. The volume of dry air is circulated at a rate of 50milliliters of air per hour per gram of catalyst during calcination.

Any element of Group VIb of the Periodic Table may be used for catalyticdemetallization in the present invention. Molybdenum and tungsten arepreferably used, as oxides or sulfides in their final reactive form,preferably in quantities ranging from about 6 to about 25% by weight (asoxide) with respect to the total weight of the catalyst. As specieswithin Group VIII of the Periodic Table, nickel and cobalt arepreferred, as sulfides in their ultimate form and preferably inquantities ranging between about 1 and 5% with respect to the totalweight of the catalyst, calculated as oxide.

After impregnation and calcination, the catalyst is next sulfurized attemperatures between 200° and 400° C., at either atmospheric or higherpressures using elementary sulfur, sulfur compounds such as mercaptansor mixtures of hydrogen and hydrogen sulfide, or mixtures thereof.

The completed catalyst has the following spectroscopic properties. Asdetermiend by x-ray photoelectron spectroscopy (XPS), the catalystexhibits a signal band strength ratio I(Me VIb)/I(refractory metal)which ranges from 5 to 8, where Me VIb is the Group VIb metal selected.Similarly, I(Me VIII)/I(refractory metal) ranges from 1 to 5.

The catalyst reveals no important information when subjected to x-raydiffraction spectroscopy. Infrared spectroscopy shows an intense peakbetween 930 and 950 cm⁻¹, which is characteristic of Co--Mo or Ni--Mobonds. On the other hand, only a poorly defined signal occurs between950 and 960 cm⁻¹, which indicates that undesirable polymolybdate ispresent in small quantities only.

The following examples are given in order to more fully describe, butnot to limit, the invention.

EXAMPLE 1

To test the effectiveness of the catalyst according to the presentinvention in demetallizing and desulfurizing hydrocarbons of petroleumorigin, Venezuelan heavy crudes were used as experimental chargestockswhich generally contain 300 ppm of nickel, vanadium and iron, 7 to 12%by weight of Conradson carbon, 5 to 10% by weight of asphaltenes, and 3to 5% by weight of sulfur. These heavy crudes were subjected to asimultaneous demetallization and desulfurization using the catalyst ofthe present invention in the presence of hydrogen at a temperatureranging between 360° and 415° C., a pressure ranging between 600 and3000 psi, a liquid hourly space velocity (LHSV) between 0.1 to 10volumes per volume-hour and a H₂ :feed ratio of from 2000 to 6000SCF/bbl.

In this example, comparative tests of initial catalytic activities weremade using a catalyst of the prior art and a catalyst according to thepresent invention. The physical-chemical characteristics of theconventional catalyst (I) and of the catalyst of the invention (F) aresummed up in Table I.

                  TABLE I                                                         ______________________________________                                        EXAMPLE 1: PHYSICAL AND                                                       CHEMICAL PROPERTIES OF CATALYST I AND F                                                      CATALYST                                                                        I           F                                                Properties       (prior art) (invention)                                      ______________________________________                                        % MoO.sub.3, by weight                                                                         14.5        5.8                                              % CoO            5.1         --                                               % NiO            --           0.98                                            % Al.sub.2 O.sub.3                                                                             complement  complement                                       Surface area, m.sup.2 /gram                                                                    285         177                                              Total pore volume, ml/gram                                                                      0.64        0.84                                            Average pore diameter, Å                                                                   7.sup.-     189                                              Bulk crushing strength, kg/cm.sup.2                                                            10.3         1.72                                            Pellet size, inches                                                                            1/16        1/16                                             Pore volume distribution, %                                                                    --          --                                               20-30 Å      2.8         0.0                                              30-60 Å      40.3        0.0                                              60-90 Å      51.6        0.0                                              90-150 Å     6.3         24.39                                            150-300 Å    1.6         65.85                                            300-10.sup.3 Å                                                                             --           6.10                                            >10.sup.3 Å               3.66                                            ______________________________________                                    

The catalytic activity of Catalysts I and F were compared by testingthem on a Venezuelan Morichal crude. The crude treated had 338 ppmvanadium, 2.7% sulfur, 10.7% Conradson carbon, 8.25% asphaltenes and hada specific gravity of 11.7 °API. A sample of this crude was put intocontact with the aforementioned catalysts at a temperature of 400° C., apressure of 1500 psi, a liquid hourly space velocity (LHSV) of 1 h⁻¹ andan H₂ :batch volumetric ratio of 800 m³ (STP)/m³. The results are shownin Table II, wherein "%HDS" and "%HDV" are percentagehydrodesulfurization and hydrodemetallization, respectively.

                  TABLE II                                                        ______________________________________                                        EXAMPLE I: INITIAL CATALYST ACTIVITY                                          CATALYST % HDS     % HDV     S = % HDV/% HDV                                  ______________________________________                                        I (prior art)                                                                          45.3      29.1      1.55                                             F (invention)                                                                          65.9      55.4      1.19                                             ______________________________________                                    

EXAMPLE 2

A series of experiments measuring demetallizing and desulfurizingactivity were conducted using seven different catalysts made accordingto the invention. The chemical and physical properties of thesecatalysts, labelled A through G, are set out in Table III.

                                      TABLE III                                   __________________________________________________________________________    EXAMPLE II: PHYSICAL AND CHEMICAL                                             PROPERTIES OF TESTED CATALYSTS                                                CATALYST      A   B   C   D   E   F   G                                       __________________________________________________________________________    MoO.sub.3, % by weight                                                                      12.9                                                                              15.0                                                                              13.4                                                                              8.1 6.0 5.8 5.9                                     CoO, % by weight  3.5 3.6 --  --  --  --                                      NiO, % by weight                                                                            2.4 --  --  1.7 1.9 0.98                                                                              2.2                                     Surface Area (BET),                                                                         79  300 292 177 168 177 140                                     m.sup.2 /gram                                                                 Pore Volume, cc/gram                                                                        0.75                                                                              1.07                                                                              1.06                                                                              0.67                                                                              0.86                                                                              0.84                                                                              0.88                                    Average Pore Diameter, Å                                                                379 143 145 151 204 189 251                                     Bed Density, grams/cc                                                                       0.83                                                                              0.41                                                                              0.82                                                                              0.58                                                                              0.53                                                                              0.47                                                                              0.41                                    Real Density, grams/cc                                                                      2.37                                                                              5.58                                                                              6.14                                                                              4.77                                                                              4.07                                                                              4.30                                                                              3.69                                    Apparent Density, grams/cc                                                                  0.83                                                                              0.77                                                                              0.56                                                                              1.10                                                                              0.93                                                                              0.93                                                                              0.87                                    Pellet Crushing Strength,                                                                   4.95                                                                              3.0 --  Fragile                                                                           2.16                                                                              Fragile                                                                           2.00                                    kg/pellet                                                                     Bulk Crushing Strength,                                                                     --  7.16                                                                              7.12                                                                              --  6.17                                                                              1.72                                                                              5.89                                    kg/cm.sup.2                                                                   Pore Distribution, %:                                                         20-30 Å   3.97                                                                               -- --  14.41                                                                             --  --  --                                      30-60 Å   0.65                                                                              19.30                                                                             2.94                                                                              14.41                                                                             --  --  --                                      60-90 Å   2.64                                                                              19.10                                                                             37.25                                                                             10.81                                                                             --  --  4.00                                    90-150 Å  13.93                                                                             13.08                                                                             11.76                                                                             19.82                                                                             20.51                                                                             24.39                                                                             10.67                                   150-300 Å 58.74                                                                             7.13                                                                              8.82                                                                              28.82                                                                             71.53                                                                             65.85                                                                             13.33                                   300-10.sup.3 Å                                                                          17.22                                                                             3.57                                                                              6.86                                                                              5.41                                                                              6.98                                                                              6.10                                                                              17.33                                   >10.sup.3 Å                                                                             2.65                                                                              38.05                                                                             32.35                                                                             6.31                                                                              0.98                                                                              3.66                                                                              54.67                                   __________________________________________________________________________

In addition, similar tests were conducted for prior art catalyst I,whose properties can be found in Table I.

The experimental conditions and hydrocarbon feedstock used in thesetests were the same as those of Example 1.

The results of the tests are compiled in FIG. 1, which plots totalcatalyst pore volume against demetallization constant K_(v) ^('), anddesulfurization constant K_(s) ^(').

FIG. 1 shows that catalysts E, F and G, which each have a total porevolume of from 0.8 to 0.9 ml/gram, have significant simultaneousdemetallizing and desulfurizing activity. Catalysts B and C, which havea pore volume greater than 1.0 ml/gram, have a greater demetallizingactivity than desulfurizing activity. Finally, conventional catalyst Ihas a significant desulfurizing activity only.

FIG. 2 plots the average pore diameter of the catalysts versus theirobserved demetallization and desulfurization constants K_(v) ^(') andK_(s) ^('). These data show that in order for a catalyst to havesignificant simultaneous demetallization and desulfurization activity,the average pore diameter should range between 200 and 300 Angstroms.

EXAMPLE 3

In this example, catalysts E, F and G, which showed simultaneousdemetallizing and desulfurizing activity in Example 2, were modified soas to increase the active metal concentrations in order to show that theobserved simultaneous effects were not due to low metallic contents.MoO₃ was increased up to about 15% by weight of the catalyst, and theconcentration of NiO was increased to about 5%.

Table IV shows that the ratio of demetallization to desulfurizationactivities does not change with the increase in active metals content ofthe catalysts.

                  TABLE IV                                                        ______________________________________                                        EXAMPLE 3: INFLUENCE OF METALLIC                                              CONTENT ON RELATIVE HDV AND HDS ACTIVITY                                      CATALYST % MoO.sub.3                                                                              % NiO   S = % HDS/% HDV                                   ______________________________________                                        F        5.8        0.98    1.18                                              F-1      14.3       4.20    1.20                                              E        6.0        1.90    1.20                                              E-1      15.3       5.00    1.18                                              G        5.9        2.20    1.12                                              G-1      14.8       4.80    1.10                                              ______________________________________                                    

EXAMPLE 4

Catalysts E and F of Examples 1 and 2 were tested in order to study therelation between signal band strength ratio as obtained by x-rayphotoelectron spectroscopy (XPS) and the demetallizing and desulfurizingactivity of the catalysts on whole heavy crudes. All catalysts werepresulfurized in the manner described earlier in the specification. Theresults obtained are shown in Table V.

                  TABLE V                                                         ______________________________________                                        EXAMPLE 4: RELATION BETWEEN XPS                                               RATIO I(Mo3d)/I(Al2p) AND                                                     HDS AND HDV ACTIVITY OF THE CATALYSTS                                                   I(Mo3d)/       %      %                                             Catalyst  I(Al2p)        HDS    HDV                                           ______________________________________                                        F-1       5              20     58                                            F-2       8              50     59                                            F-3       9              60     60                                            E-1       9              70     68                                            E-2       5              30     69                                            ______________________________________                                    

From Table V it can be seen that there is a strong relation between thesimultaneous demetallization and desulfurization of heavy crudes and theI(Mo3d)/I(Al2p) signal band strength ratio of the catalysts. Reductionof this signal band strength ratio is uniformly accompanied by adecrease in the HDS activity of the catalysts.

EXAMPLE 5

The catalysts E and F of Examples 1 and 2 and conventional catalyst Iwere tested in order to study their useful lives in demetallizing anddesulfurizing a continuous feed of heavy crude. The experimentalconditions were as follows: T=400° C.; hydrogen pressure=1500 psi;LHSV=1 h⁻¹ and H₂ :feed=1000 m³ (STP)/m³. The results obtained are shownin Table VI.

                  TABLE VI                                                        ______________________________________                                        EXAMPLE 5: CATALYTIC                                                          ACTIVITIES OVER USEFUL LIVES OF CATALYSTS                                                % HDS       % HDV                                                               Initial  Final    Initial                                                                              Final                                   CATALYST     24 hours 80 days  24 hours                                                                             80 days                                 ______________________________________                                        I            50       30       29      0                                      (CONVENTIONAL)                                                                F            70       65       60     60                                      (INVENTION)                                                                   ______________________________________                                    

The results of the preceding table clearly show the effectiveness of thecatalyst of the present invention for the simultaneous and stabledemetallization and desulfurization of heavy crude feeds or theirderivatives which have high metal and sulfur contents.

EXAMPLE 6

The catalyst F of Example 1 and conventional catalyst I of Example 5were tested in order to study their useful lives in demetallizing anddesulfurizing a continuous feed of Cerro Negro Residual 350° C.+. Theexperimental conditions were as follows: T=400° C., Hydrogenpressure=1800 psig; LHSV=1 h⁻¹ and H₂ /Feed=1000 Nm³ /m³. The propertiesof Residual 350° C.+ are summarized in Table VII.

                  TABLE VII                                                       ______________________________________                                         CHARACTERISTICS OF                                                           RESIDUAL 350° C. + CERRO NEGRO                                                           Residual 350° C. +                                   Properties        Cerro Negro                                                 ______________________________________                                        API gravity       5.2                                                         Viscosity Cst, 140° F.                                                                   3500                                                        Conradson Carbon, % by Wt                                                                       17.1                                                        Asphaltenes, % by Wt                                                                            12.1                                                        Sulfur, % by Wt   4.53                                                        Nitrogen, ppm     7700                                                        Vanadium, ppm     535                                                         ______________________________________                                    

Table VIII shows the results obtained with catalysts F and I. Catalyst Fshows a substantial increase in the HDS and HDV catalytic activitiesover catalyst I. It may be seen that the new catalyst remains stable formore than 220 days, while catalyst I fails irreversibly after 70operating days.

                  TABLE VIII                                                      ______________________________________                                        CATALYTIC ACTIVITIES OVER                                                     USEFUL LIVES OF CATALYSTS                                                     CATA-   % HDS            % HDV                                                LYSTS   24 h   80 day   220 day                                                                              24 h 80 day                                                                              220 day                             ______________________________________                                        I       40     25       15     20    0    --                                  (Prior Art)                                                                   F       68     65       62     70   70    69                                  (Invention)                                                                   ______________________________________                                    

Without doubt, the newly developed catalyst is an attractive alternativeto conventional catalysts when used for the hydrotreatment of heavycrudes and residues.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiments are therefore to be considered as inall respects illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, and all changes whichcome within the meaning and range of equivalency are intended to beembraced therein.

What is claimed is:
 1. A process for the hydrotreatment of a heavyhydrocarbon feedstock containing high levels of nickel and vanadiumcontaminants, sulfur and asphaltenes comprising the steps of: contactingsaid heavy hydrocarbon feedstock with a catalyst characterized bysimulteneous demetallizing and desulfurizing activity wherein the ratioof percent of demetallizing to desulfurizing approaches unity over auseful life in excess of 80 days in a reactor at a temperature varyingbetween 300° and 450° C., a pressure varying between 600 and 3500 psig,a linear hourly space velocity varying from 0.05 to 5 (hours)⁻¹, a H₂:feed ratio ranging from 300 to 20,000 SCF/bbl and a partial hydrogenpressure of from 500 to 3000 psig; said catalyst comprising an aluminasupport material impregnated with a first compound consistingessentially of a metallic compound whose metallic compound is selectedfrom Group VIB of the Periodic Table, disposed on said alumina supportmaterial so as to comprise from 5 to 30% of the catalyst by weight,calculated as an oxide and a second compound consisting essentially of ametallic compound whose metallic component is selected from Group VIIIof the Periodic Table, disposed on said support material so as tocomprise from 0.1 to 8% of the catalyst by weight, calculated as anoxide; a total pore volume ranging from between 0.50 to 1.20 ml/g; anaverage pore diameter of about between 200 to 300 Å and signal bandstrength ratios, as determined by x-ray photoelectron spectroscopy, asfollows: I(Me VIb)/I(refractory metal) is between 5 and 8 and I(MeVIII)/I(refractory metal) is between 1 and
 5. 2. A process according toclaim 1 wherein the average pore diameter is about between 240 to 280 Å.